Description

Does the object exist?

The two examples below give the same result.

using UnityEngine;

public class Example : MonoBehaviour
{
// check if there is a rigidbody attached to this transform
void Start()
{
if (GetComponent<Rigidbody>())
{
Debug.Log("Rigidbody attached to this transform");
}
}
}

...is the same as this...

using UnityEngine;

public class Example : MonoBehaviour
{
// check if there is a rigidbody attached to this transform
void Start()
{
if (GetComponent<Rigidbody>() != null)
{
Debug.Log("Rigidbody attached to this transform");
}
}
}